Fair Value Measurement - Fair Value Level 3 Rollforward Recurring Basis (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
FG VIEs’ Assets at Fair Value
Fair Value Level 3 Rollforward
Fair value at beginning of period	$ 318	$ 526	$ 442	$ 569
Total Pretax Realized And Unrealized Gains (Losses) Recorded As Assets [Abstract]
Net income (loss)	8	6	(79)	70
Other comprehensive income (loss)	0	0	0	0
Purchases	0	0	0	0
Sales	0		0
Settlements	(12)	(69)	(67)	(170)
FG VIE consolidation		(6)	18	6
FG VIE deconsolidation				6
Transfers into Level 3				0
Transfers out of Level 3			0
Fair value at end of period	314	469	314	469
Change in unrealized gains/(losses) related to financial instruments held	8	6	(2)	78
Corporate securities
Fair Value Level 3 Rollforward
Fair value at beginning of period	60		47
Total Pretax Realized And Unrealized Gains (Losses) Recorded As Assets [Abstract]
Net income (loss)	2		10
Other comprehensive income (loss)	0		0
Purchases	0		5
Sales	0		0
Settlements	0		0
FG VIE consolidation			0
Transfers out of Level 3			0
Fair value at end of period	62		62
Change in unrealized gains/(losses) related to financial instruments held	2		10
Equity securities and warrants
Fair Value Level 3 Rollforward
Fair value at beginning of period	53		17
Total Pretax Realized And Unrealized Gains (Losses) Recorded As Assets [Abstract]
Net income (loss)	6		9
Other comprehensive income (loss)	0		0
Purchases	5		55
Sales	(21)		(38)
Settlements	0		0
FG VIE consolidation			0
Transfers out of Level 3			0
Fair value at end of period	43		43
Change in unrealized gains/(losses) related to financial instruments held	5		8
Structured products
Fair Value Level 3 Rollforward
Fair value at beginning of period	6		0
Total Pretax Realized And Unrealized Gains (Losses) Recorded As Assets [Abstract]
Net income (loss)	0		3
Other comprehensive income (loss)	0		0
Purchases	0		17
Sales	(6)		(20)
Settlements	0		0
FG VIE consolidation			0
Transfers out of Level 3			0
Fair value at end of period	0		0
Change in unrealized gains/(losses) related to financial instruments held	0		0
Other Assets and Other Invested Assets
Fair Value Level 3 Rollforward
Fair value at beginning of period	78	87	55	77
Total Pretax Realized And Unrealized Gains (Losses) Recorded As Assets [Abstract]
Net income (loss)	(10)	(14)	13	(4)
Other comprehensive income (loss)	0	0	0	0
Purchases	0	0	0	0
Sales	0		0
Settlements	0	0	0	0
FG VIE consolidation		0	0	0
FG VIE deconsolidation				0
Transfers into Level 3				0
Transfers out of Level 3			0
Fair value at end of period	68	73	68	73
Change in unrealized gains/(losses) related to financial instruments held	(10)	(14)	13	(4)
FG VIEs' liabilities with recourse, at fair value
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Fair value at start of period	(332)	(446)	(367)	(517)
Total Pretax Realized And Unrealized Gains (Losses) Recorded As Liabilities [Abstract]
Net income (loss)	(9)	(2)	(5)	(33)
Other comprehensive income (loss)	(4)	1	2	6
Purchases		0		0
Issuances	0		0
Settlements	9	64	50	156
FG VIE consolidation		5	(16)	(5)
FG VIE deconsolidation				5
Transfers into Level 3				0
Fair value at end of period	(336)	(388)	(336)	(388)
Change in unrealized gains/(losses) included in earnings related to financial instruments held as of September 30, 2020	(7)	(2)	(3)	(32)
Change in unrealized gains/(losses) included in OCI related to financial instruments held at September 30. 2019	(4)	1	2	6
Variable Interest Liabilities without Recourse
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Fair value at start of period	(20)	(105)	(102)	(102)
Total Pretax Realized And Unrealized Gains (Losses) Recorded As Liabilities [Abstract]
Net income (loss)	(1)	(2)	73	(9)
Other comprehensive income (loss)	0	0	0	0
Purchases		0		0
Issuances	0		0
Settlements	2	3	13	6
FG VIE consolidation		1	(3)	(1)
FG VIE deconsolidation				1
Transfers into Level 3				0
Fair value at end of period	(19)	(105)	(19)	(105)
Change in unrealized gains/(losses) included in earnings related to financial instruments held as of September 30, 2020	(1)	(1)	(2)	(16)
Liabilities of Consolidated Investment Vehicles
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Fair value at start of period	(806)		(481)
Total Pretax Realized And Unrealized Gains (Losses) Recorded As Liabilities [Abstract]
Net income (loss)	(24)		13
Other comprehensive income (loss)	0		0
Issuances	0		(362)
Settlements	0		0
FG VIE consolidation			0
Fair value at end of period	(830)		(830)
Change in unrealized gains/(losses) included in earnings related to financial instruments held as of September 30, 2020	(24)		13
Obligations of state and political subdivisions | Fixed-maturity securities
Fair Value Level 3 Rollforward
Fair value at beginning of period	97	105	107	99
Total Pretax Realized And Unrealized Gains (Losses) Recorded As Assets [Abstract]
Net income (loss)	2	3	4	5
Other comprehensive income (loss)	(5)	(4)	(16)	1
Purchases	0	6	0	6
Sales	0		0
Settlements	(1)	(1)	(2)	(2)
FG VIE consolidation		0	0	0
FG VIE deconsolidation				0
Transfers into Level 3				0
Transfers out of Level 3			0
Fair value at end of period	93	109	93	109
Change in unrealized gains/(losses) included in OCI related to financial instruments held at September 30. 2019	(5)	(4)	(16)	1
Corporate securities | Fixed-maturity securities
Fair Value Level 3 Rollforward
Fair value at beginning of period	29	48	41	56
Total Pretax Realized And Unrealized Gains (Losses) Recorded As Assets [Abstract]
Net income (loss)	1	1	(5)	(9)
Other comprehensive income (loss)	0	(3)	(6)	(1)
Purchases	0	0	0	0
Sales	0		0
Settlements	0	0	0	0
FG VIE consolidation		0	0	0
FG VIE deconsolidation				0
Transfers into Level 3				0
Transfers out of Level 3			0
Fair value at end of period	30	46	30	46
Change in unrealized gains/(losses) included in OCI related to financial instruments held at September 30. 2019	0	(3)	(6)	(1)
RMBS | Fixed-maturity securities
Fair Value Level 3 Rollforward
Fair value at beginning of period	254	325	308	309
Total Pretax Realized And Unrealized Gains (Losses) Recorded As Assets [Abstract]
Net income (loss)	5	5	10	16
Other comprehensive income (loss)	9	1	(26)	21
Purchases	0	0	0	11
Sales	0		0
Settlements	(11)	(15)	(35)	(41)
FG VIE consolidation		0	0	0
FG VIE deconsolidation				0
Transfers into Level 3				0
Transfers out of Level 3			0
Fair value at end of period	257	316	257	316
Change in unrealized gains/(losses) included in OCI related to financial instruments held at September 30. 2019	9	1	(24)	21
Asset-backed securities | Fixed-maturity securities
Fair Value Level 3 Rollforward
Fair value at beginning of period	714	674	658	947
Total Pretax Realized And Unrealized Gains (Losses) Recorded As Assets [Abstract]
Net income (loss)	7	7	21	51
Other comprehensive income (loss)	26	(3)	(16)	(97)
Purchases	172	1	290	19
Sales	(19)		(42)
Settlements	(3)	(15)	(13)	(257)
FG VIE consolidation		0	0	0
FG VIE deconsolidation				0
Transfers into Level 3				1
Transfers out of Level 3			(1)
Fair value at end of period	897	664	897	664
Change in unrealized gains/(losses) included in OCI related to financial instruments held at September 30. 2019	26	(2)	(17)	8
Credit Risk Contract
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Roll Forward]
Fair value at start of period	(161)	(216)	(185)	(207)
Total Pretax Realized And Unrealized Gains (Losses) Recorded As Net Derivative Asset (Liability) [Abstract]
Net income (loss)	(3)	5	20	(25)
Other comprehensive income (loss)	0	0	0	0
Purchases		0		0
Settlements	5	3	6	24
Issuances	0		0
FG VIE consolidations		0	0	0
FG VIE deconsolidation				0
Transfers into Level 3				0
Fair value at end of period	(159)	(208)	(159)	(208)
Change in unrealized gains/(losses) included in earnings related to financial instruments held as of September 30, 2019	$ 1	$ 8	$ 28	$ (19)